Author's Note: I'll probably update this every week or so.

"Leo..." Donnie whispered, trembling. Leo's cold, blue eyes just stared at them silently. He didn't move an inch at all. "..Why..? Out of all our enemies.." Donnie continued, suddenly boiling with both anger and sadness. "You joined Shredder?!"

"He's been with us since last year, right Leo?" Karai spoke, smiling maliciously. Leo only looked at Karai and nodded. "He's also been pretty silent, but he's done a lot for the Foot Clan." Karai finished.

Raph gritted his teeth in anger, "Leo.. have you gone INSANE?!" He screamed. Leo's eyes narrowed and his grip on a katana tightened. "You've been missing for a year, and this is all you do!?" Raph yelled again. "If (Y/N) was still here, she'd be very disappointed."

The sudden mention made Leo pin Raph to the ground in a blink of an eye, Donnie and Mikey gasped when they saw Leo's blade at Raph's throat. His blue eyes were narrowed into slits.

"Don't ever mention that name ever again." His voice was deep and scary, "If you do, I won't hesitate to slice your throat." He growled and got up from his position, walking back to Karai. "Shredder ordered us to be back there just a while ago, we have to go." Leo spoke.

"Alright. Until we meet again, turtles." Karai smiled evilly, and she disappeared with Leo and the remaining Footbots in a cloud of smoke.

No sound came from the three turtle brothers, they were all frozen in their own thoughts. Their eldest brother, Leonardo, joined their worst enemy. Raph was the first to move, as he started punching the concrete.

"Raph!" Donnie exclaimed and tried stopping the hothead, but to no avail. Raph kept punching until his hands were bloody, almost to the point where his knuckles were going to break. "STOP!"

Raph stopped, he was panting heavily, then put his head in his hands and trembled.

"Raph..." Donnie spoke softly.

"He's gone." Raph said, "Just like that, he's gone." He added. Mikey only stood there, whimpering at how much he's seen today. "You know what that means?"

Donnie stayed silent, not knowing what or how to answer.

"Our big brother will never come back." Raph answered after a long pause of silence. He stood up and started walking, "Let's go." Raph muttered.

"But.. what about-"

"Forget the mutagen. Let's just go." Raph snapped, Donnie sighed, grabbed Mikey and they walked in silence.

In Shredder's Lair...

Shredder sat on his throne alongside Rahzar and Tigerclaw as they waited for Karai, Leo and the Footbots. The doors opened as they appeared.

Karai and Leo bowed respectively, "Father, we've secured the mutagen."

"Excellent." Shredder said in his cold voice, "Did the turtles come?"

"As expected." Karai said, "They didn't realize that their brother works for us, now." Karai added, Leo stayed silent again.

"They're fools." Shredder said, he looked at Rahzar. "Rahzar, you, Karai and the Footbots will do the second mission tomorrow, you will also lead them."

"Yes, Master Shredder." Rahzar bowed respectively.

"What about Leonardo, master?" Tigerclaw asked, pointing to Leo who kneeled down still.

"I'll train him so he can be a full Foot soldier." Shredder said, this caused Leo's head to look up in interest. "All of you, dismiss. Leonardo, remain here."

Everyone else bowed and left the room, while Leo stood up and sat where Tigerclaw was.

"What is it, master?" Leo asked respectfully.

"Come." Shredder said in a softer tone than a while ago and stood up. Leonardo obliged and followed him into a room, when the lights were turned on, Leo saw armor, weapons and lots of Japanese warfare inside.

Leo looked around in awe. Shredder walked to a large metal cabinet and opened it to reveal tough, metal armor with the Foot Clan symbol on the shoulder armor.

"Whoa.." Leo said quietly.

"It was mine before, but now that I have new armor, I'm giving it to you." Shredder said and touched the armor. Leo's eyes widened.

"Are you sure, master?" Leo asked.

"I insist. It does suit you, young one." Shredder said and closed the metal cabinet.

"When can I wear it?" Leo asked again.

"In time, you may wear it. Once you're ready." Shredder spoke and walked out of the room. Leo stayed there by the cabinet.

He touched the cold metal and looked at his reflection, he saw himself as a Foot soldier, but he could faintly see himself as a Hamato Clan soldier. He shook his head.

No, Shredder's my master now Leo thought and walked out the room.

To Be Continued...